


I Won't Hold My Breath

by Amethystina



Category: Marvel Cinematic Universe
Genre: Angst, Asphyxiation, But also, Gas chambers as plot device, Gassing, Heroic Tony, ImagineTonyandBucky Prompt Fill, Insecure Tony, Let's pretend Age of Ultron and everything that came after it never happened, M/M, Misunderstandings, Not Actually Unrequited Love, mentions of nazis
Language: English
Status: Completed
Published: 2017-06-03
Updated: 2017-06-03
Packaged: 2018-11-08 16:51:20
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,605
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11085837
Author URL: https://archiveofourown.org/users/Amethystina/pseuds/Amethystina
Summary: Falling in love with Captain America's boyfriend is no doubt at the top of the list of Tony's most stupid accomplishments. He knows Bucky would never choose him above Steve — not when the two super soldiers have been fighting for seventy years to find their way back to each other. Fact is, even Tony finds that ridiculously romantic and wouldn'tdreamof interfering. More than anything, he wants Bucky to be happy.So when Steve and Tony find themselves trapped inside an old HYDRA base during a mission, slowly being gassed to death, the choice to put Steve's life above his own is easy. Captain America is more important than Iron Man, and Bucky Barnes needs Steve Rogers a whole lot more than he would ever need Tony Stark.





	I Won't Hold My Breath

**Author's Note:**

> _**Prompt by[snnaaft](https://snnaaft.tumblr.com/):** Tony, who is falling hard for Bucky believes Steve and Bucky are together. They were because it was easy but broke up before Bucky fell b/c they realized how it can be when Steve met Peggy. Bucky has fallen for Tony, but believes Tony would never want him. Tony sacrifices himself to save Steve (in mouth to mouth scene from 616 Red Zone arc). He does this because he thinks Steve is more important than him, specifically to Bucky. Then Tony and Bucky get together and live happily ever after._
> 
> Another prompt fill for [ImagineTonyandBucky](http://imaginetonyandbucky.tumblr.com/)! One that I managed to keep surprisingly short. I admit that I haven’t read the particular comic arc referenced in the prompt (though I am familiar with the scene) so I made up a MCU equivalent instead. It still has a lot of angst and a happy ending, soooo mission accomplished, right?
> 
> [Shi_Toyu](http://archiveofourown.org/users/Shi_Toyu) was kind enough to beta — you truly are amazing, love — and you can find my Tumblr [here](http://amethystinawrites.tumblr.com/). Have fun reading!
> 
>    
>  **WARNING:** In this story a rather blunt statement is made about Nazis and gassing which might be triggering for those of you who have family history relating to the Holocaust. There are no mentions of the Nazi ideology — nor does this story condone it — but references _are_ made to Nazis and the way they killed during the Holocaust. Please be safe.

 

The moment the steel doors slammed shut behind him and Steve, Tony knew his day was going to end badly. Nothing good ever happened in supposedly abandoned HYDRA bases — even less so if it involved doors locking on their own. The fact that their perfectly functional comms channel suddenly crackled with static was another dead giveaway.

This was supposed to be a routine mission — just one more facility to tick off their long list of HYDRA bases to search and destroy — but something had obviously gone wrong. HYDRA must have been expecting them and set up a trap of some kind.

Steve, ever the optimist, was trying to pry open the door. "Check the other one," he said.

Tony did as told, his gaze wandering over the narrow steel corridor as he crossed it, but nothing popped out as particularly dangerous. There were no windows, no furniture, and no HYDRA goons. It was just him and Steve and, as expected, two firmly locked doors.

"I can't reach the others over the comms," Tony reported, allowing the helmet to fold away. "My connection to JARVIS is patchy too. There's something in this room that blocks the signal."

Steve gave up on the door and looked around, but he probably wouldn't find anything Tony hadn't already seen — mostly because there wasn't much to see.

"Keep trying to reach the others," Steve said, frowning at the closed door as it if was a puzzle in need of solving — possibly through the liberal use of super soldier strength.

Again, Tony did as told. The rest of the team were somewhere in the facility, having split up to cover more ground. Someone had to notice that Tony and Steve weren't responding over the comms, but whether or not they knew where to find them was another question. If the room blocked their radios, it might be blocking their trackers as well.

Somehow, Tony wasn't surprised that out of _all_ the people he could end up get locked into a room with, he got Steve. That was just his luck.

It wasn't that he disliked the man — Tony considered Steve to be one of his closest friends — but things had been, well, a little _awkward_ lately. The fault lay entirely with Tony and his inability to keep his raging hormones in check, and spending time with Steve wasn't as easy as it once had been.

In his defense, Tony had never _planned_ to fall in love with Captain America's boyfriend — he wasn't _that_ stupid — it just happened, without his consent or input.

Tony knew perfectly well that Steve and Bucky had been an item back during the war. If the rare snapshots and movie reels of the two of them smiling longingly at each other hadn't been enough to reach that conclusion, the look on Steve's face when he'd first brought the subdued Bucky to the Avengers Tower certainly was. Steve had looked like a man who had just found the missing piece of his heart, and even Tony could admit that was unbelievably romantic.

Steve and Bucky's love transcended time, wars, and brainwashing Nazis, and of course Tony had wanted to protect something that pure. So he'd made a place for Bucky in the tower, right next to Steve, and supplied the lawyers who protected Bucky from lawsuits and being thrown in prison.

A friend of Steve's was a friend of Tony's.

There _had_ been that rather significant speed bump of Bucky breaking down and confessing to murdering Tony's parents, but they had gotten past that too. It took work, granted, but Tony was willing to do whatever necessary to make Bucky relax and heal. He deserved to feel safe and protected after all those years in HYDRA's clutches.

Naturally, Tony had fucked it all up by falling in love with the guy, but he felt he couldn't be blamed for that. Bucky was _amazing_.

Once he grew less haunted and paranoid — mainly thanks to _a lot_ of therapy — Bucky was a really great guy. He had exactly the kind of dry, teasing sense of humor that Tony loved, and every time he smiled or laughed Tony could feel his heart skip a beat. And, on top of that, he turned out to be breathtakingly kind and considerate, often bringing Tony food when he'd been down in the workshop for too long without eating.

So _of course_ Tony had fallen in love with him, even if he knew perfectly well just how stupid that was. He couldn't compete with _Steve_ — no one could. Steve was _Captain America_ , for heaven's sake, and he had waited seventy years to be reunited with Bucky. After everything the two of them had been through, they deserved their happily ever after. Nothing could — or should — ever come between them.

Tony certainly wasn't going to try. He was jealous of them, sure, but he would never dream of doing anything that might ruin their happiness.

"Any luck with the comms?" Steve asked, coming to stand next to Tony.

"I can hear bits and pieces," Tony replied, pressing a metal finger against his earpiece, "but mostly just static. The suit is transmitting an emergency alert, but I can't guarantee that the others will pick up on it."

Steve frowned, obviously thrumming with pent-up energy. He might be a master tactician, but he always grew impatient when missions stalled unexpectedly. Given another couple of minutes, Tony suspected Steve might even start bouncing on the balls of his feet.

"We need to find a way out," Steve said, as if that wasn't already obvious. His gaze swept over the narrow corridor once more. "The vents?" he suggested.

Tony couldn't help a fond snort. "You know I love your optimism, Cap, but not even Nat could squeeze through those vents, let alone you or me."

"There's got to be something we can do."

"I'm sure there is," Tony replied, "but I think we might be better off waiting for the others to get here. They'll be able to—"

The suit's helmet suddenly snapped back into place, startling Tony enough to make him jump. For a brief moment, he wondered if the armor was malfunctioning too — he hadn't given any kind of command — but then he saw the alarm flashing on the HUD.

Tony's stomach dropped. "Cap, we have a problem."

"What?"

"The suit's emergency systems just kicked in. It's picking up on some form of contamination in the air — a gas of some kind, coming from the vents. It's still at a relatively low level, but it seems to be rising." Tony tried to interpret the readings, but this wasn't any substance he recognized. "I can't say for sure what it does, but my guess is 'something bad'."

That would explain the tightly sealed corridor, if nothing else. HYDRA was going to gas them to death, like proper Nazis.

Steve gritted his teeth, looking from one vent to the other, but there were too many of them to cover up — not to mention that they didn't have anything to cover them _with_.

"Are you good?" Steve asked. "Does the suit protect you?"

Tony swallowed, eyes flicking over the numbers. "Yes, more or less. The filters are working at maximum capacity, but I'll manage for at least an hour or two." He looked at Steve, his stomach twisting. "What about you?"

"Well," Steve said, his voice suspiciously light, "I can hold my breath for about six minutes. After that we'll have to think of something else."

Tony's mind was already whirring with possibilities. "I can detach my helmet. The filters only work at about fifty percent when not sealed together with the rest of the armor, but if we passed it back and forth between us—"

"No," Steve interrupted, "keep the helmet on. I might be more resilient than you thanks to the serum, and it's better for one of us to keep a clear head."

It took everything Tony had not to protest. Objectively and tactically speaking, Steve was right, but that didn't make it any easier for Tony to accept.

He would just have to get them out before their six minutes were up.

"Fine, but you better shut up and start holding your breath, Cap," he snapped back. "The less you breathe in of this stuff, the better. And don't move, either. You conserve more oxygen if you stay still."

Steve held up his hands in surrender and did as told. Tony wished he could say that he was happy to see Steve be obedient for once, but the situation took all the fun out of it. If Tony didn't get them out soon, he might have to watch Steve suffocate.

There was no use freaking out about that yet, however. Tony still had at least five minutes to find a solution, and he had a literal arsenal at his disposal. The problem was that he wasn't sure if he could risk firing any of the missiles or even his repulsors. If the gas was flammable, the only thing he'd succeed in doing was turn the corridor into a burning inferno.

Neither of them was likely to survive that.

"JARVIS, can you hear me?" Tony was back by the first door, trying to find weak spots he might be able to exploit.

"Sir, there is someth— block—" Static crackled over the channel, making the next couple of words impossible to decipher. The fact that Tony still had a connection was comforting, but HYDRA was somehow blocking their transmissions.

"I guess I'll have to figure this out on my own," Tony mumbled, gauntlets wandering over the scratched metal.

There were no cracks or dents that he could see, and whatever mechanism controlled the doors had to be on the other side. Tony cursed under his breath and contemplated whether or not he could risk firing his repulsors. According to the suit's readings, the gas wasn't flammable at first glance, but there were elements it couldn't identify — not without JARVIS's help — and those might be.

Tony glanced back at Steve. He hadn't moved, just as ordered. Unfortunately, him standing there with his eyes closed, absolutely motionless, only made Tony more nervous. He couldn't let Steve die here. Not only was he one of Tony's closest friends, but he was a shining beacon of hope to so many. The world would be devastated if it lost Captain America.

 _Bucky_ would be devastated.

Tony swallowed down the lump in his throat and focused back on the door — the clock was ticking. He had to get them out. That was easier said than done, however. There was no handle and no hinges to break, he couldn't get good enough purchase to pry the doors apart, and not even punching them seemed to help.

Tony might have tried that last one mostly out of desperation.

The comms were still crackling, and the few snippets Tony did pick up didn't give him much to go on — he had no idea if the others were looking for them. The suit was still sending out the emergency alert, but there was no way for Tony to know if it had reached his teammates.

There was a sudden sound behind him and Tony whirled around, his heart leaping into his throat. Steve was down on one knee, his palm pressed flat against the metal floor. Even if he was doing an admirable job of fighting it, Steve was sucking in deep gulps of contaminated air.

"No!" Tony rushed over, the suit whirring as he fell to his knees. "Steve, you can't—"

"I have—" Steve gasped, "—to breathe... at some point."

That was true, Tony knew that — everyone lost the battle against their body's reflexes eventually — but there was too much of the foreign gas. What Steve was breathing in wouldn't sustain him. It would, in all probability, just end up killing him.

"Okay, time for plan B." Tony reached for his helmet but Steve was faster, grabbing one of Tony's wrists.

"No." He shook his head, each breath a struggle. "Don't. That's... an order."

"Steve, don't be ridiculous," Tony pleaded. "I can't watch you die."

He would never be able to look Bucky in the eyes again if he let Steve die.

It was obvious that Steve intended to reply, but he never got that far. His eyelids fluttered, and a second later he slumped forwards into Tony's arms. Had Tony not been wearing the suit, he probably wouldn't have been able to brace for all the extra weight.

"Steve?" Tony's heartbeats echoed loudly in his ears. "Steve!"

There was no reply.

Panic clawed through Tony, his throat tight. Gently, as carefully as possible, he laid Steve down on the floor and pressed a hand against his chest. There was a faint rise and fall. Steve was still breathing, but probably not for long.

"Fucking hell." Tony ignored the slight crack in his voice and called up the unsteady comms channel. "Can anyone hear me? Avengers, come in. Cap and I need help, immediately. Avengers?"

Tony swallowed and looked down at Steve — good, loyal, and precious Steve. He knew what he had to do. It wasn't much of a decision, really.

The world didn't need Tony Stark, but it might actually fall apart without Captain America.

Tony knew Bucky would. After being separated for so many long, excruciating years, Bucky and Steve had finally found each other again. They deserved to be together — they deserved happiness. Tony couldn't let Steve die like this, not when he knew that he could save him. If that meant Tony had to die in his stead, well, that was a price Tony was willing to pay.

Bucky needed Steve a lot more than he would ever need Tony. If one of them had to die, it should be Tony.

Steve's chest stilled under Tony's hand.

He had to make a decision.

After a deep, fortifying breath, Tony reached up and took off his helmet. The suit's alarms started blaring, but Tony ignored them, quickly placing the helmet next to him on the floor. He had to move fast.

The gauntlets folded back and Tony pressed his fingers against Steve's neck, finding a faint but noticeable pulse. Without wasting time he tilted Steve's chin up, pinched his nose, and leaned down to breathe into his mouth. Just that wouldn't save him, though — not if the air Tony kept pushing into his lung was contaminated. That would only make Steve sicker.

What Tony needed to do was to get Steve to start breathing on his own again, then give him the helmet. That was the only way. The helmet would give Steve enough oxygen to survive. It would leave Tony completely without anything to protect him, sure, but at least it would save Steve.

Tony couldn't let Steve die here — not when he had Bucky waiting for him.

Thankfully, Tony was always prepared for the possibility that he might not make it through the day. Ever since the episode with the arc reactor, he'd made sure to keep his will up-to-date. Pepper would get his shares of the company and some of the estates. Rhodey would get the suits and another batch of estates. Happy would get the cars and a third gathering of estates. The Avengers would get the tower and every piece of equipment Tony had ever designed for them. Whatever was left — including the actual money he owned — would be donated to various charities, most notably the Maria Stark Foundation.

Tony didn't _want_ to die, but at least he could do it without making too much of a mess. Besides, sacrificing himself to save a national icon was a much more noble death than he'd ever thought he'd get. All things considered, it wasn't a bad way to go.

There was a sudden, loud crackle over the comms, making Tony jump. After a while, he managed to make out words — the voice achingly familiar.

"—where are— come on, answer— Steve!"

 _Bucky_.

Even if it had only been brief glimpses, there had been no mistaking the fear in Bucky's voice.

"Don't worry," Tony mumbled in between ventilations, blinking away the black spots dancing across his vision. Even if Tony tried not to breathe in too much of the gas, his head was already spinning. He doubted Bucky heard him, but it felt good to say the words. "I'll save him. I won't let him die."

He'd do it for Bucky.

It only took five ventilations before Steve's chest started rising on its own again, however weakly. Tony praised the supersoldier serum — and Steve's general stubbornness — and fumbled for the helmet. Despite how badly his hands were shaking, Tony managed to slip it over Steve's head.

The surge of triumph he felt when Steve continued to breathe was enough to make Tony laugh, choked and half-dazed.

Steve would be fine.

Tony swallowed and rose to his feet. Without the suit, he wouldn't have been strong enough, but it compensated for his shaking limbs. As soon as Tony was standing more or less straight, he let the suit fold away.

If Tony was about to die, he didn't want it to be inside the armor.

His knees buckled and he fell unceremoniously to the floor, landing on his stomach next to Steve. There was a loud, echoing pounding in Tony's head, and he knew he didn't have much time. He reached out, his hand trembling, and placed it against Steve's chest.

It rose and fell, rose and fell.

Tony almost whimpered from relief. Steve would be fine.

Bucky wouldn't have to lose the man he loved.

The floor was cold against Tony's cheek. His breaths grew shorter, shallow and almost gasping, but that was fine. Tony had done what he needed to do. Steve would live. That was all that mattered.

The banging continued, loud and incessant — too loud to be Tony's heartbeats.

Surprisingly, dying didn't hurt. He was just tired — so incredibly tired.

Tony closed his eyes. He could feel Steve's chest move underneath his palm, and decided it was okay to stop fighting the drowsiness.

Before everything faded into nothingness, Tony thought he heard someone scream his name, but he knew that was only his wishful thinking.

Tony breathed out and let go.

 

* * *

 

The first surprise was that Tony woke up to find himself in the Avenger's sickbay; he hadn't expected to wake up at all.

The second surprise was that Bucky Barnes was sitting at his bedside, looking like he'd been to hell and back. His eyes were red-rimmed, his shoulders tense, and he was sporting an even more impressive stubble than usual. Tony hadn't seen Bucky look so haunted since he'd first joined them at the tower — when he still jumped at shadows and had nightmares that left him quiet and distant for days.

"Uh," was all Tony managed, feeling suitably disoriented. There was a dull throb of pain in his skull and his chest felt tight, to the point where he had a little trouble breathing properly. It almost felt like he had the arc reactor again, pressing against his lungs. Aside from that, though, Tony felt surprisingly fine — especially since he had expected to be dead.

Bucky's head snapped up, his eyes wide and glassy with unmistakable grief. Tony had done everything in his power to get Steve out of that room alive, just to avoid having to see that look on Bucky's face.

He had saved Steve, right?

"Tony." Bucky's voice was so frail it nearly broke. "You—"

"Steve?" Tony croaked, trying to push down the panic. He had to know. He had to know if he had cost Bucky the love of his life.

Bucky shut his mouth with a clack and averted his gaze. That was a bad sign. Tony braced himself for the bad news and berated himself for not having acted sooner. He should have ignored Steve's orders and just forced the bloody helmet onto his head, because now Steve was dead and Bucky looked like he was breaking and Tony couldn't bear—

"He's fine," Bucky replied.

Tony's thoughts screeched to a halt. "What?" he asked dumbly, throat raw.

Bucky gritted his teeth. "He's fine. They discharged him yesterday."

That made no sense. Bucky looked devastated, but Steve was fine.

"You're worse off," Bucky continued, still not meeting Tony's gaze. "The gas might have caused lingerin' damage to your heart. The doctors are running some tests." His voice was soft. "And they'll want to check for brain damage too, now that you're awake."

"Okay," Tony replied. He'd had worse, and knew the medical routine fairly well after so many years as an Avenger. What he couldn't understand was why Bucky looked so distraught. "Aren't you happy about Steve?" Tony was almost wheezing at the end of the sentence, running out of breath much quicker than usual. He assumed it was because of the gas he had inhaled.

"'Course I am," Bucky said but, in reality, he looked just about ready to cry. "'m happy he's okay. I don't... I wouldn't know what to do without him."

The familiar twist in Tony's chest — like a knife being turned — was oddly comforting. It offered him some much needed stability.

"I just..." Bucky's jaw was tightly clenched, his gaze resting somewhere around Tony's right shoulder. "Why did you do that?" There was so much accusation in his tone.

Tony frowned. "Do what?"

"You took your fuckin' helmet off!" Bucky snapped. The outburst was unnecessary loud, but it looked like Bucky needed the outlet. His eyes were a little wild. "I know Steve wouldn't have let you. So why would—" Bucky swallowed, his breath trembling. "You could have _died_ , Tony."

What little stability Tony had gained was gone yet again. He was officially out of his depth. Perhaps he could blame it on the fact that he had recently woken up from a traumatizing event?

"I had to save Steve," Tony replied. Bucky, if anyone, should know how important Steve was. "Did you want him to die?"

"No!" Bucky looked horrified. "Of course not. I don't want either of you to die. But why would—" He cut himself off and turned his gaze away.

Tony didn't know what to say. None of this made sense. Why was Bucky so upset?

Bucky rubbed a hand over his face, his stubble making a scratching sound against his palm. He looked exhausted, and Tony couldn't understand that either. Why was Bucky here and not with Steve? How long had he been sitting at Tony's bedside?

"I understand why you did it." Bucky's words were so soft that Tony barely caught them. "I would have too, but I can't—" It sounded like Bucky really was about to cry. "I thought you were dead. I had to carry you out of that room and you weren't movin' or breathin' and I didn't know what to do."

Tony stared, stunned, as the first tear trickled down Bucky's cheek. He hadn't thought Bucky cared that much. They were friends, sure, but that was it. Tony might want them to be more, but he knew Bucky didn't.

Bucky had Steve.

Without warning, Bucky got to his feet, his chair scraping noisily against the floor. Another tear fell, but Bucky wiped it away with a rough hand.

"I know I shouldn't do this — I don't want to pressure you and now's a really bad time — but after what happened..." Bucky sounded so desperate it made Tony's heart ache. "I can't go through that again. I have to tell you."

"Tell me what?" Tony asked faintly.

Bucky met his gaze and there was so much grief and guilt in his eyes, but also breathtaking determination.

"I love you."

Tony blinked.

"I know I shouldn't — I told myself not to fall in love with you — but I can't help it." The smile on Bucky's lips looked pained, rife with sadness as it was. "You never flinch away or treat me like I'm breakable. I can _breathe_ around you and for once not worry about my past and all the horrible things I've done. You even forgave me for what I did to your parents." Bucky swallowed and looked down at his hands. "You make me feel less broken, like I'm still human underneath this mess I've become."

Tony was speechless. He knew he should reply — there was a steadily growing ball of joy in his chest, begging to be set free — but he was too surprised to find the words.

Bucky loved him? _Him_?

"I'm so sorry, Tony." Bucky looked away, shame clear on his face. "I know you probably won't ever want someone like me, with so much blood on their hands, but I—"

"Wait, what?" Tony blurted out, finally regaining his ability to speak. "But what about Steve?" he asked dumbly.

It was Bucky's turn to look surprised. "What about him?"

Why did Tony have to spell it out for Bucky?

"You two are together."

Bucky frowned. "Not anymore. We split before the war ended."

"You... what?" Tony was beginning to feel a little lightheaded. Luckily, he could lean back against his pillows while he tried to reboot his brain.

A silence settled over the room. Tony wasn't sure what to say, so he guessed it was fortunate that Bucky did.

"You think I'm with Steve?"

"Well... yeah. Who wouldn't, the way you act?" Tony had to pause to catch his breath and, in the meantime, gestured vaguely towards Bucky. "With the whole star-crossed lovers and—" another breath, "—the longing gazes and the... everything."

Bucky hesitated for a couple of seconds before taking a seat on the edge of Tony's bed. "Tony, I'm not in love with Steve. He and I shared a lot back then, I admit — includin' a bed — but not anymore." There was sincerity in his words and a steadily growing confidence in his eyes.

Tony swallowed. "Oh." He looked at Bucky. "Well, now I feel like an idiot."

There was another silence, though this one was significantly shorter.

"You're not upset about me bein' in love with you?" Bucky asked softly, and there was no mistaking the hope in his voice.

"What? No, of course not. I—" Tony cleared his throat, barely managing to hold back a cough, "—I'm quite happy to hear it, in fact."

A slow, shy smile spread on Bucky's lips. "Oh?"

"Yeah." Tony's heart was racing. "That makes the fact that I'm in love with you a lot easier to deal with."

Tentatively, as if afraid that Tony would pull back, Bucky took Tony's hand in his, lacing their fingers together. "I know you deserve so much better than me, but—"

"Let me be the judge of that, okay?" Tony knew it was rude to interrupt, but he had no intention of allowing Bucky to head down that road. There were few people as worthy as Bucky.

Another couple of seconds passed, Bucky rubbing soothing circles against the back of Tony's hand.

"So, how about a date?" Bucky suggested. His words were firmer and the desperation had been replaced by confidence.

"Well, I need to get discharged first." Tony smiled. "But after that I'm all yours."

"I like the sound of that." Bucky's playfulness was returning, his responding smile enough to make Tony's heart to skip a beat. Bucky reached out with his free hand and reverently stroked Tony's cheek. "I like it a lot," he said, voice tender.

Tony exhaled, leaning into the touch. "Me too," he replied, just as softly.

While yesterday might have ended pretty badly for Tony, today and tomorrow were definitely looking up.

 

**Author's Note:**

> I hope you enjoyed it! Take care, my lovelies!


End file.
